Fuel shut-off apparatus



Jan. 13, 1959 e. w. CORNELIUS 2,863,132

FUEL SHUT-OFF APPARATUS Filed Oct. 17, 1955 3 Sheets-Sheet 1 46 INVENTOR.

1 7 iomifi/C'be/yzz/w NW BY Jan. 13, 1959 G. w. CORNELIUS 2,868,182

FUEL SHUT-OFF APPARATUS Filed Oct. 17, 1955 5 Sheets-Sheet 2 United States FUEL snur-orr APPARATUS George W. Cornelius, Portuguese Bend, Calif., assignor to Holley Carburetor Company, Van Dyke, Mich.

The present invention relates generally to internal combustion engines and more particularly to a novel fuel shut-off apparatus for use therewith.

It is well known that the unburned products of combustion exhausted from internal combustion engines of automotive vehicles constitute a prime source of the socalled smog which exists in an around the principal population centers of the country. The harmful effect of this smog upon animate and inanimate objects are likewise very well known. Since the inception of smog and recognition of its detrimental effect upon health and plant life, extensive research has been carried on to find ways and means of diminishing the internal combustion engine's contribution to smog. Much attention has been given to the deceleration cycle, at which time there is no useful work accomplished through the combustion of fuel and at which time, it has been determined, the largest percentage of unburned products of combustionare exhausted from the engine. These unburnedproducts of combustion result from the fact that during the time the engine is being rotated under the momentum of the vehicle at a speed greater than that obtained by the carburetor throttle setting, an extreme vacuum exists within the engines cylinders and intake manifold. This high vacuum tends to draw fuel from the carburetor into the combustion chambers of the engine. The existence of this high vacum does not permit adequate compression within the combustion chambers to take place and accordingly the fuel failsto undergo complete burning. These unburned hydrocarbons are exhausted into the atmosphere where they contribute to the smog-content. Additionally, the existence of these unburned hydrocarhon products form carbon deposits within the combustion chambers and the exhaust 'valve ports and remainder of the exhaust system. These disadvantages are in addition to the reduction in mileage resulting from the loss of fuel from the carburetor during deceleration. The deceleration period is utilized, to a certain extent, for the purpose of slowing down or contributing braking effect to the vehicle. This is particularly true on grades sufiiciently steep to effect an overrunning condition where the forward motion of the vehicle is cranking the engine against compression. It has been found that in cases where the fuel is completely shut off from the engine during periods of deceleration, a greater force is required to crank it at overrunning speeds. It therefore follows that with an effective fuel shut-off the braking effect during deceleration is improved.

in an effort to overcome these disadvantages it has been I heretofore-proposed to provide automatic shut-off devices for positively stopping the flow of fuel to an engine during deceleration thereof. The devices which have been employed for this purpose, however, have not met with any notable acceptance. With most of the heretofore-proposed fuel shut-off devices, the fuel has been shut off at a point in the carburetor above the idle metering orifice. With this arrangementthe fuel is dried out in the passage or passages between the point of shut-off and atom: G

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the outlet of the idling well orifice during deceleration. Hence, when the throttle is again opened to resume normal engine operation a time lag is required for the fuel to again commence flow into the intake manifold from the carburetor. During this time lag, the engine will operate with a disagreeable roughness and occasional backfiring and stalling. Another disadvantage with the heretoforeproposed devices of this nature stems from their use of control methods which are too delicate to withstand the normal wear and tear to which the average automobile engine is subjected. Yet another disadvantage results from the tendency of these heretofore-proposed shut-off devices to malfunction after a period of use due to the build-up of fuel-carried foreign material on their working parts.

It is a major object of the present invention to provide an improved form of fuel shut-off apparatus.

Another object is to provide a fuel shut-off apparatus which permits the fuel to commence flowing into the intake manifold from the carburetor prior to or simul taneously with a re-opening of the throttle after a period of deceleration.

A further object is to provide a fuel shut-off apparatus which is extremely sensitive in action and is capable of shutting off and turning on the fuel in the shortest possible time.

An additional object is to provide a fuel shut-off apparatus incorporating novel means for positively rendering it inoperative except during a deceleration period.

It is yet a further object of the invention to provide a fuel shut-off apparatus which is simple in design and rugged of construction whereby it may afford a long and trouble-free service life.

An additional object of the invention is to provide apparatus of the aforedescribed nature which incorporates an auxiliary automatic shut-off device for stopping the flow of fuel to the float chamber of the carburetor at the same time that the flow of fuel within the carburetor throat is shut off.

Yet a further object of the invention is to provide fuel shut-off apparatus that may be readily installed upon the engine of any conventional automotive vehicle.

Another object is to provide fuel shut-off apparatus which is not affected by fuel-carried foreign matter and which requires a minimum amount of maintenance.

These and other objects and advantages of the present invention will become apparent from the following de tailed description, when taken in conjunction with the appended drawings, wherein:

Figure l is a side elevational view of a preferred form of fuel shut-off apparatus embodying the present invention mounted upon an internal combustion engine;

Figure 2 is an enlarged central vertical sectional view of a regulator device forming a part of said apparatus;

Figure 2a is a fragmentary further enlarged vieW of a detail of said regulator device;

Figure 3 is an enlarged central vertical sectional view of a portion of Figure 2 showing the mode of operation of an element thereof;

Figure 4 is an enlarged vertical sectional view taken on lines 44 of Figure 3;

Figure 5 is an enlarged central vertical sectional view taken along line 55 of Figure l, and showing shutoff member forming a part of said apparatus;

Figure 6 is a vertical sectional view taken on line 6--6 of Figure 5;

Figure 7 is a vertical sectional view taken on line 7-7 of Figure 6;

Figure 8 is an enlarged central vertical sectional view of a float chamber shut-off member incorporated in said apparatus;

Figure 9 is an enlarged horizontal sectional view taken on line 9-9 of Figure 1;

Figure 10 is an end view taken from a point designated by the arrow in Figure 9;

Figure 11 is an enlarged vertical sectional view taken along line ll11 of Figure 10 and showing a limit valve and an auxiliary limit valve incorporated in said apparatus; and

Figure 12 is an enlarged vertical sectional view of a modified form of said limit valve.

General arrangement a butterfly-type throttle valve 29 which is keyed to a horizontal shaft 22. This shaft 22 passes through the walls 24 of the carbueretor so as to support the throttle valve for pivotal movement relative thereto. One end of the'shaft 22 protrudes through the carburetor walls 24 so as to receive the throttle arm 26. The latter is connected to the accelerator pedal of the automotive vehicle wherein the engine E is mounted by suitable linkage means 28. With this arrangement, and referring to Figures 1, 2, 3 and 7, counterclockwise rotation of the throttle arm 26 will eflect movement of the throttle valve 20 from its closed or idling position of Figure 2 towards an open position shown in Figure 3. The throttle valve 20 is normally biased towards its closed position of Figure 2 by suitable spring means (not shown).

The preferred form of fuel shut-off apparatus embodying the present invention includes a regulator valve R shown mounted at the lower right hand side of Figure 1, a limit valve L mounted to the left and above the regulator valve, an auxiliary limit valve LA adjacent the limit valve L, an air-fuel shut-off member S mounted above the limit valve L, and a float chamber shut-01f member F mounted above the air-fuel shutoff member. These five members are inter-related and operate in the following general manner. Referring to Figures 5, 6 and 7, the air-fuel shut-off member S cooperates with an idling fuel Well or passage 3% formed in the walls 24 of the carburetor C, to effect a positive stoppage of the fuel entering the carburetor throat 32 during deceleration of the engine E. To this end, the

air-fuel shut-off member S includes a metering pin, generally designated 34, which is disposed in its open or dotted outline position of Figures 5 and 7 during operation of the engine other than when the latter is decelerating. During deceleration this metering pin will be moved to the right to its closed or solid line position of Figures 5 and 7. The primary sensing means for effecting operation of the air-fuel shut-off member S is the regulator valve R that is shown in detail in Figures 2 and 2a. The motivating force for operating the regulator valve R is the intake manifold pressure of the engine E. The limit valve L and the auxiliary limit valve LA cooperate with the regulator valve R in effecting operation of the air-fuel shut-off member 8. The limit valve L prevents inadvertent actuation of the air-fuel shut-off member S during open-throttle engine operating conditions Where the throttle is closed slightly but is not permitted to close to a full idling position. The auxiliary limit valve LA controls operation of the air-fuel shut-off member S during times when the engine is de-clutched. The float chamber shut-off member F functions simultaneously with the air-fuel shutoff member S and operates to positively cut off the flow of fuel to the float chamber of the carburetor C during deceleration conditions. 7 7

The regulator valve R With particular reference to Figures 2 and 2a the regulator valve R includes a body, generally designated 40, and a bonnet 42 which is threaded into the upper portion thereof. The body is centrally formed with a vertical bore 44 wherein is slidably mounted the stem 46 of a valve member 48. The stem 46 is formed with a cylindrical cavity 49 and its lower end is rigidly affixed to the head 50 of the valve member 43, while the underside of this head 50 is secured to a flexible metallic diaphragm 52. The periphery of the diaphragm 52 is secured to the underside of the body 40 by a threaded cap member 53 wherein are formed apertures 54. The upper end of the valve stem 46 is formed with a piston element 55'. The piston element 55, and hence the valve member 48, are constantly biased downwardly by a helical compression spring 56. The adjustment of this spring 56 may be controlled by an adjustment bolt 57 which is threadably carried by the upper end of the bonnet 42. The spring 56 and the lower portion of the adjustment bolt 57 are disposed within a cylindrical cavity 58 formed in the bonnet 42. This cavity 58 is in communication with the atmosphere through suitable filter material 59. The piston element 55 includes an upwardly facing sealing surface 60 and a downwardly facing sealing surface 61. The upper surface of the diaphragm 52 is connected to a conduit 68 by a passage 70 formed in the body 40.

As shown in Figure 2, the opposite end of this conduit 68 is connected to the throat 32 of the carburetor C by means of a rectangular opening 72. Conveniently, this opening 72 may be formed in a bushing element 74 1 that is rigidly aflixed to a threaded fitting 76 which is open position, however, the edge of the throttle valve moves downwardly away from this opening and the latter is thereby uncovered. With this arrangement, when the throttle valve 20 is in an open position the diaphragm 52 will be exposed to atmospheric pressure on both its upper and lower surfaces, inasmuch as during the time the rectangular opening 72 is uncovered the upper surface of the diaphragm will be placed in communication with the atmosphere through the conduit 68. When the throttle valve 20 is disposed in its closed position of Figure 2, however, the rectangular opening 72 will be covered and accordingly the upper surface of the diaphragm 52 will be exposed to the intake manifold vacuum existing below the throttle valve. The spring 56 should be so adjusted that it will exert suflicient downward force against the piston element 55 that the diaphragm 52 cannot flex upwardly under the influence of the vacuum existing underneath the throttle valve 20 during idling. The diaphragm should be capable of upward flexure, however, under the influence of the higher vacuums which result during deceleration conditions. Upward movement of the piston element 55 from its solid outline position in Figure 2a to its dotted outline position therein serves to place a passage 78 formed in the right side of the body 40 with a second passage 80 formed in the left side of this body by means of an annular space 63 between the upper and lower sealing surfaces 60 and 61, respectively, of the piston element 55. As shown in Figure l, the first passage 78 is in communication with the intake manifold I by means of a conduit 82. It should be noted that the intake manifold pressure is constantly balanced with regard to its effect upon the vertical movemeat of the piston element 55, inasmuch as the first passage 78' empties into the annular space 63. The second passage 80 is connected to the auxiliary limit valve LA by means of a conduit 84.

. Referring particularly to Figure 2a, in order to obtain a quicker action of the regulator valve R anopen-topped cup 86 is slidably disposed within the cylindrical cavity 49 of the stem. 46.. The bottom wall 87,0f this cup is rigidly afiixed to an upstanding tube 88. The upper end of this tube 88 is of frusto-conical configuration and is formed with vents,89. .The upper end of the tube 88 is adapted to seat against the lower end of a vertical passage 90 centrally formed in the piston 55, Theinterior 7 in the stem 46. The underside of the cup 86 is vented to atmosphere by a vent 95 formed through the lower portion of the body 40. With this arrangement, the spring 93 will forcev the cup 86 ari d hence the upper end of the tube 88 downwardly when the vacuum existing within the stem cavity 40 falls to a predetermined value, i. e. when the engines throttle is opened from its idling or deceleration position, v Atmospheric pressure will then be immediately admitted to the uppersurface of the diaphragm 52 and the latter will accordingly tend to snap downwardly to its solid. outline position of Figures 2 and 2a.

. The air-fuel shut-0]} member S As'indicated previously,-the air-fuel shut-off member S includes a metering pin, generally designated 34. This meteringpin 34 is axially slidably disposed withina bore 97. formed in the mainbody, generally designated 98, of the shut-off member S. The front portion of this body 98 is formed with an externally threaded nipple element 100 which is threadably secured within an internally threaded cavity 102 formed in one side of the carburetor wall '24. The front portion of the bore 97 terminates in a venturi 104, the front end of which constitutes the orifice of the idling well 30. This venturi 104 is adapted to mix both air and fuel before they enter the carburetor throat 32. As shown in Figures 5, 6 and 7, the fuel enters the idling well 30 through a diagonal passageway 106 formed in the carburetor wall 24 and a plurality of radially extending ports 108 having their radially inner ends terminating within the throat of the venturi 104. Conveniently, an adjustment needle 109 may be disposed in the passageway 106 for controlling the flow of fuel into the venturi 104. Air enters the venturi 104 through a horizontal passage 110 formed in the carburetor wall 24, the interior of a retainer element 111 carried by the nipple 90 and a plurality of radially extending ports 112 formed in the latter. These ports 112 are in communication with the bore 97 rearwardly of the venturi 104.

The rear portion of the main body 98 is formed with a cup element 113, the interior of which constitutes a coaxial continuation of the bore 97. The rear of the cup 113 is closed by a closure element 114that is centrally formed with a threaded bore 115. The latter bore threadably mounts a fitting 116 which is secured to the closure member by a lock nut 117. The fitting 116 is coaxially formed with a passage 118 aligned with the bore 97 of the main body98. The rear endof this passage 118 is in communication with a smaller counterbore 120. The latter is in turn adapted to be placed in communication with the interior of the limit valve L by means of a conduit 122.

The intermediate portion of the metering pin 34 is formed with a guide collar 124 having its rear end rigidly afiixed to the front wall 126 of a metallic bellows 128.

d The rear end of this metallic bellows 128 is in turn rigidly affixed to the closure element 114. A helical compression'spring 130 is interposed between the front wall 126 of the bellows and the front surface of the rear closure manner to be set forth hereinafter, the metering pin will be retracted to its closed position of Figures 5 and 7.

it should be particularly noted that the front end of the metering pin 34 isformed with a generally conical plug element 136 which. tapers radially outwardly and forwardly away from the front of the idling well 30. With this arrangement, the metering pin will open away from the static pressure of the fuel thereby aiding in the .initial resumption of fuel delivery through the venturi 104 into the carburetor throat 32. It will also be apparent that the plug element .136 of the metering pin, as well as the orifice of the idling well 30 upon which it seats is constantly exposed to the slip stream of the air passing through the carburetor throat 32 during engine operation. The slip stream thus serves to keep these elements clean with respect to foreign material carried by the fuel.

It should be likewise noted that in the apparatus of the present invention, the throttle valve 20 when disposed in a closed or idling -positionis completely seated with vrespect to the carburetor throat 32. This is not true in the conventional carburetion system wherein the throttle valve is normally left partly open and the air required for idling passesdownwardly around the periphery of this throttle valve past the idling well. With the conventional carburetion system, after the engine has been operating for some time, foreign matter will collect on the periphery of the throttle valve so as to shut off a portion of the air passing downwardly into the intake manifold. When this occurs, the air/ fuel ratio becomes richer. It will be obvious that this results in a wastage of fuel. With the apparatus of the present invention, such wastage is eliminated inasmuch as the air required for idling by-pas ses the completely closed throttle valve 20, as shown in Figures 5, 6 and 7. Accordingly, once the proper air/ fuel ratio is obtained it need not be changed. An additional advantage of the present system results from the fact that during deceleration, a considerable quantity of fuel will collect behind the plug element 136. Hence, when the metering pin 34 is re-opened, a very rich starting mixture will be provided. in this manner there will be but slight tendency for the engine to run roughly when the throttle is reopened. Furthermore, the light ends of the fuel may reach the intake ports of each combustion chamber at approximately the same time as the air inasmuch as they enter the carburetor throat 32 simultaneously. The limit valve L Referring now to Figures 9, l0 and ll, the limit valve L includes a body, generally designated 140, formed at its left end with a cylindrical cavity 142. The front of this cavity 142 is closed by a fitting member 143 having an integral nipple 144 to which is attached one end of a conduit 145. As shown in Figure l, the opposite end of this conduit 145 is selectively connected to the regulator valve R under the control of the auxiliary limit valve LA in a manner to be described hereinafter. The body 140 is likewise formed with a passage 146 which intersects the rear portion of the cavity 142. A poppet valve element 148 having its, stem 150 slidably disposed within a bore 152 formed in the body 140 in alignment with the cavity 142 is adapted to control communication between the conduit 145 and the passage 146. A helical compression spring 153 is interposed between the inner end of the cavity 142 and the underside of the head of the poppet valve 148. The portion of the cavity 142 between the underside of this head and the inner end of the cavity is in communication with the atmosphere by means of a plurality of radially extending ports 156 formed in the body 140. The radially outer ends of these ports 156 are surrounded by a suitable filter 158. The free end of the poppet valves stem 150 is connected to one arm 160 of a generally L-shaped pivot link 162 having its mid-portion pivotally secured to the body 140 by a pin 164. The opposite arm 166 of the pivot link 162 is afiixed to an abutment plate 168 by a bolt 170. The free end of this abutment plate 168 carries an adjustment bolt 172. The head of this adjustment bolt 172 is adapted to be engaged by a bumper element 174 which is rigidly affixed to a horizontally extending rod 176 forming a part of the throttle valve actuating linkage means 28. The bumper 174 and the adjustment bolt 172 are so arranged that the final movement of the throttle valve to its closed or idling position Will cause the bumper to engage the head of the adjustment bolt and thereby effect clockwise rotation of the pivot link 162 from its dotted to its solid outline position of Figure 11. When this occurs, the head of the poppet valve 148 Will likewise be moved from its dotted to its solid outline position in this figure. Communication may then take place between the conduit 145 and the passage 146. The latter passage 146 is incommunication with the fitting 116 of the air-fuel shut-off member S by a nipple 178 and the conduit 122 secured thereto.

The auxiliary limit valve LA Referring now to Figures 9 and 11, the auxiliary limit valve LA is shown mountedadjacent the lower lefthand end of the limit valve L. The construction of this auxiliary limit valve LA corresponds to that of the limit valve L and hence a detailed description thereof is not believed necessary. In Figure 11 the visible parts of the auxiliary limit valve LA corresponding to those of the limit valve L are designated by primed reference numerals.

The nipple 144' of the auxiliary limit valve LA is connected to the conduit 84 leading to the regulator valve R. The nipple 178 of the auxiliary limit valve LA is connected to the conduit 145. As in the case of the limit valve L, the poppet valve 148' is constantly biased to the left relative to Figure 11 so as to cut off communication between the conduits 84 and 145 by the helical compression spring 153'. The poppet valve 148 is adapted to be moved to the right so as to permit communication between the conduits 84 and 145 when the head of the adjustment bolt 172 is engaged by a bumper element 181 secured to a rod 176' forming a part of the engine clutching linkage of the vehicle wherein the apparatus is installed. This clutching linkage may constitute a part of the manually operated clutch system of a vehicle having a standard transmission, or a part of the drive linkage of an automatic transmission. In either case, the poppet valve 148 is disposed in its right-hand position relative to Figure 11 so as to permit communication between the conduits 84 and 145 only when the engine E is connected to the wheels of the vehicle wherein the apparatus is installed, as indicated by solid outline in this figure. When the engine E is de-clutched from these wheels, the bumper element 181 will be disengaged from the bolt 172 and the spring 153' will snap the poppet valve 148' to the left so as to cut off communication between conduits 179 and 180, as shown by its dotted outline in Figure 11.

The float chamber shut-off member F Referring now to Figures 1 and 8, the float chamber shut-off member F includes a mounting element 181 at its front end which is formed with an externally threaded nipple 182 adapted to screw into a carburetor boss 184 which leads into the float chamber (not shown) of the carburetoi'C. The float chamber shut-ofi member F also includes a body member 186 which is formed with an internally threaded socket 188 for receiving the engines fuel line 190. The front portion of the body 186 is formed with a coaxial bore 192 which is in alignment with an annular passage 193 formed at the front portion of the socket 188. A valve member 194 is axially slidably disposed within the bore 192. This valve member 194 includes a central passageway 196 having an open front end and having a plurality of radially extending ports 198 formed at its rear portion. The rear end of the valve member 194 is conical and is movable towards and away fromthe passage 193 under the influence of a flexible metallic diaphragm 202. The central portion of the diaphragm 202 isrig'idly secured to the front end of the valve-member 194 by a nut 204. The periphery of the diaphragm 202 is rigidly supported within a generally cylindrical case 206 which'is formed between the front portion of the body 186 and the rear portion of the mounting element 180. A helical compression spring 208 is carried by the front end of the body 184 for constantly biasing the valve member 194 forwardly so as to unseat its conical rear end from the front of the passage 193. The rear surface of the diaphragm 202 is adapted to be placed in communication with the conduit 122 by means of a fitting 210, a length of conduit 212 and a Y-shaped connector214, as shown in Figure l.

The conduit 122 is connected to the limit valve L.

' v Operation In the operation of the aforedescribed preferred form of fuel shut-off apparatus, during engine operating conditions other than deceleration and idling,.the throttle valve 20 will be disposed in its open position'of Figures 3 and 7. With the throttle valve open, the rectangular opening 72 will be uncovered so as to place the upper surface of the diaphragm 52 of the regulator valve R in communication with atmosphere. Accordingly, the regulator valves spring 56 will maintain the piston element 55 in its lower dotted outline position of Figure 2. With the piston element 55 so disposed, communication between the two passages 78 and formed in the opposite sides of the regulator valve R will be cut off. When the throttle valve 20 moves to its closed position of Figure 2, however, the upper portion of the rectangular opening 72 will be closed by the edge of the throttle valve. The upper surface of the diaphragm 52 will then be placed in communication with the engines intake manifold pressure. If it is assumed that the engine is decelerating, the intake manifold pressure will be of a sufficient magnitude that the diaphragm 52 will undergo upward fiexure to its solid line position of Figure 2, thus lifting the piston element 55. The two passages 78 and 80 will then be placed in communication and in this manner the conduit 84 will be connected to the pressure of the intake manifold I.

It should be particularly noted that the use of the aforedescribed regulator valve R permits the air-fuel shut-off member S to be actuated by the full vacuum existing within the intake manifold. This is a decided advantage over the heretofore-proposed devices wherein the motivating force for the fuel shut-off member is dependent upon a 'diiferential intake manifold pressure. It will be apparent that positive operation of a fuel shut-off member is difficult to achieve where only a few pounds per square inch pressure is available for operation.

Referring now to Figures 9, 10 and 11, the conduit 84 extending from the regulator valve R is connected to the fitting member 144 extending from the left side of the auxiliary limit valve LA. Assuming that the engine remains drivingly connected to the wheels during decleration, the poppet valve 148' of the auxiliary limit valve LA will be disposed in its right-hand or solid outline be in communication. Additionally, when the drivers footis raised. from the accelerator pedal so as to close the throttle valve 29, the bumper element 174 on the horizontal rod 176 will engage theadjustment bolt 172' of the. limit valve L and, as described'hereinabove, will cause the head of the poppet'valve: 148 to move to the right against the fo rce'of' the spring 153 Such movement of the poppet valve148 will place the passage 146 and hence the conduit 122m communication with the conduit 145. Asno-tedhereinabove,the latter conduit 145 is. connected by conduit"84 tothe intake manifold I when the throttle'valve 20 is closed during deceleration.

Referring now to Figure 5, the opposite end of the conduit 122 is connected to the fitting 116 of the air-fuel shut-off member S.- Accordingly, the interior of the bellows 128 will then be placed in communication with the intake manifold pressure. The introduction of intake manifold pressure to the interior of the belows 128 will effect movement of the bellows, and hence the metering pin 34, to the rightin Figure soas to cause the latters plugelement 136 to seal oifthe orificeof the idling well 30. As noted above, such seating of the plug element 136 will cut off the flow of air and fuel intothe carburetor throat'32. The plug element 136 will remain seated so longas deceleration of the engine continues and the latter is not de-clutched. When the accelerator pedal is again depressed so as to open the throttle valve 20, atmospheric pressure will again be admitted through the rectangular opening 72 of the regulator valve R. Upon such occurrence both sides of the regulator valves diaphragm 52 will be exposed to atmospheric pressure, and the spring 56 will urge the piston element 55 downwardly so as to cut off communication between the" two passages 78 and 80 and hence between the conduit 84 and theintake manifold 1. Referring again to Figures 9, and 11, movernentof the accelerator linkage 28 towards an open position will also causethe bumper element 174 on the rod 176 to be moved away from the head of the adjustment boltf172. The pivot link 162 of the limit valve L will then pivot counter-clockwise to its original position, and communication will be cut off between conduits 84 and 178. I Referring now to Figure 5, when the intake manifold pressure is cut off from the interior of the bellows 128 atmospheric pressure will be vented therein from the limit valve L and the compression spring 130 will urge the front wall 126 of the bellows and hence the metering pin 34 to the left. Accordingly, the plug element 1360f the metering pin will be returned to its open position and air and fuel will again be admitted to the carburetor throat 32. If during deceleration the engine E is de-clutched the bumper element 174' will move away from the bolt 172 of the auxiliary limit switch LA so as to permit the spring 153 to move the poppet valve 148 to the left so as to cut off communication between conduits 84 and 145. This causes the, plug element 136 of the metering pin 34 to returnto its open position independently of the limit valve L. The same result will be obtained in a vehicle having an automatic transmission should the drive selector be moved to neutral. This arrangement insures that the engine will not stall in the event the driver declutches just after the vehicle has decelerated to a stop or 11ear-stop because of a lackof fuel. Instead, the op erati'on of de-clutching will cause an immediate movement of themeteringpin 34; to an open position.

Referring now to Figure 8, at the same time that the interior of the conduit 122 is in communication with the intake manifold vacuum, the pressure thereof will be transferred to the rear surface of the float valve shutoff members diaphragm 202 by means of conduit 212. Accordingly, the valve member 194 thereof, will be urged rearwardly to its solid line position of Figure 8. In this position, the valve member 194 will be seated Within the front end of the passage 193 so as to cut off the flow of fuel through the radial ports 1% and hence lto the interior of the carburetor float bowl.

ment, there is nodanger that fuel may splash out of the carburetor floatbowl and into the carburetorthroat 32 even though the automotive vehicle should be traversing rough terrain or traveling around a-curve as it decelerates. When the intake manifold pressure is no longer in communication with the'conduits 122 and 212, the compression spring 208 will again urge the diaphragm 202 and hence the valve member 194 to, their dotted line positions of Figure 8. The normal flow of fuel to the carburetor float bowl will then again take place.

Referring again to Figure 1, it should be noted that a dashpo-t 220 is shown mounted on the left side of the carburetor C. This daspot 220 is so connected" to the throttle arm 26 that final movement of the latter towards a closed position when the accelerator pedal is released takes place at a lower rate than prior movement. The utilization'of this dashpot 220 with the aforedescribed apparatus has proven to be'beneficial in re-establishing normal flow ofthe fuel through the carburetor throat after aperiod of deceleration.

' lit should be particularly observed that the utilization of the limit valve L described hereinaboveprevents inadvertent closure of the plug element 136 of the metering pin '34, during open throttle engine operation where the throttle valve 26 is permitted to close slightly from its open position. Under such conditions there would be a momentary increase in the intake manifold pressure. Without the provision of the limit' valve if suchan increase were of suflicient magnitude, it could effect a closure of the plug element 136. With the use of the limit valve L, however, even though such a surge in the intake manifold pressure raised the piston element 5501? the regulator valve R so as to connect the conduits '84, .145 and 122 with the intake manifold pressure, this pressure would not be transmitted to the air-fuel shut-off member S, inasmuchas the poppet valve 148 of the limit valve L is not unseated except during the final travel of the throttle valve actuating linkage 28 towards a closed position. It should be realized, however, that in certain installations the limit valve L and/or the auxiliary limit valve LA may be eliminated and the conduit 122 connected directly to the fitting 116 of the air-fuel shut-off member S.

Modified form 0] limit valve of Figure 12 conduit 84 leading to the regulator valve R. The poppet valve 246 is constantly biased to the left towards a closed position by helical compression spring 250. -The cavity 24-4 is connected to a passage 252 wherein is disposed a nipple 254. This nipple 254 is adapted to be attached-to the aforedescribcd conduit 122 leading to the air-fuel shut-off member S. 'The side of the body 240 remote from the conduit 84 contains an. electric solenoid 256. Thissolenoid 256 is adapted when energized to pull the poppet valve 246 to the right so as to permit communication between the conduits 84 and 122. When the solenoidis de-energized, the spring 25% will return the poppet valve 246 to the left so as to cut off communication between these two conduits. A switch 258 controls the operation of the solenoid 256 in conjunction With an auxiliary switch 260. One Side of the windings With this, arrangerent by a lead 266. The second terminal 268 of the switch 258 is connected to one of the terminals 270 of the auxiliary switch 260 by a lead 272. The other terminal 274 of the auxiliary switch 260 is connected to the source of electric current by a lead 276. The actuating button 278 of the switch 268 is engaged by theaforedescribed bumper element 174 of the throttle valve actuating linkage means. The actuating button 280 of the auxiliary switch 260 is adapted to be engaged by the aforedescribed button element 181 of the rod 176' vof the engine clutching linkage.

In the operation of this modified form of limit valve LM, when the engine E is connected with the Wheels of the vehicle wherein the apparatus is mounted, the bumper element 181 will be engaged with the actuating button 280 whereby the auxiliary switch 260 will be closed. Assuming that the throttle valve 20 is disposed in a closed position, the bumper element 174 of the throttle valve actuating linkage will be engaged with the actuating button 278 of the switch 258 and the latter will be closed. Accordingly, current will be conducted to the windings of the solenoid 256 and the poppet valve 246 will be moved to the right so as to permit communication between conduits 84 and 122. The interior of the bellows 128 of the air-fuel shut-off members S may then be placed in communication with the intake manifold I. If, however, the engine E is de-clutched the bumper element 181 will be disengaged from the actuating button 280 of the auxiliary switch 260. Thus, electric current will not be permitted to flow to the switch 258. Thus, it will be seen that the modified limit valve LM takes the place of both the aforedescribed limit valve L and auxiliary limit valve LA.

It will be apparent that various other modifications and changes may be made with respect to the foregoing description without departing from the spirit of the invention or the scope of the following claims.

I claim:

1. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a shut-off member for controlling the flow of fluid through said idling fuel passage; an opening formed in said carburetor means, said opening being substantially covered by said throttle valve when the latter is in a closed position and uncovered by said throttle valve when the latter is in an open position; and means operatively interposed between said opening and said shut-off member for effecting operation of the latter responsive to the position of said throttle valve.

2. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a pressure-responsive shut-off member for controlling the flow of fluid through said idling fuel passage; conduit means for connecting said shut-01f member to said intake manifold; an opening formed in said careburetor means, said opening being substantially covered by said throttle valve when the latter is in a closed position and uncovered by said throttle valve when the latter is in an open position; and valve means interposed in said conduit means for controlling communication between said shut-oif member and said intake manifold, said valve meansbeing connected with said opening so as to be responsive to the position of said throttle valve relative thereto.

3. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: an opening formed in said carburetor means, said opening being substantially covered by said throttle valve when the latter is in a closed position and uncovered by said throttle valve when the latter is in an open position; a pressure-responsive shutoff member for controlling the flow of fluid through said idling fuel passage; conduit means for connecting said shut-off member to said intake manifold; a regulator valve having a passage forming a portion of said conduit ,means and ablocking element movable relative to said passages for controlling flow therethrough, and a pressure-responsive wall operatively connected to said blocking means and having one of its sides exposed to a substantially constant fluid pressure; and means for placing the opposite side of said wall in communication with said opening. 7

4. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means, an intake manifold connected 'with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: an opening formed in said carburetor means, said opening being substantially covered by said throttle valve when the latter is in a closed position and uncovered by said throttle valve when the latter is in an open position; a pressure-responsive shut-off member for controlling the flow of fiuid through said idling fuel passage; conduit means for connecting said shut-off member to said intake manifold; a regulator valve formed with a passage that defines a portion of said conduitmeans and with a cavity'intersecting said passage, said regulator valve having a blocking element slidably disposed in said cavit for controlling flow through said passage, said regulator valve having sensing means responsive to the differential between atmospheric pressure and intake manifold pressure for effecting movement of said blocking element;

and means for placing said sensing means in communication with said opening.

5. Fuel shut-off apparatus as set forth in claim 4 where said sensing means includes a flexible diaphragm secured to said blocking element and exposed on one side to atmospheric pressure, and spring means constantly opposing the force exerted by such pressure against said diaphragm.

6. Fuel shut-ofl? apparatus for use with an internal combustion engine having carburetor means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: an opening formed in said carburetor means, said opening being substantially covered by said throttle valve when the latter is in a closed position and uncovered by said throttle valve when the latter is in an open position; a shut-off member for controlling the flow of fluid through said idling fuel passage, said member including a metering pin movable within said idling fuel passage between an open and a closed position, a pressure-responsive element secured to said pin for actuating same and resilient means-constantly biasing said pin toward one of said positions; conduit means for connecting said pressureresponsive element to said intake manifold; and valve means interposed in said conduit means for controlling communication between said pressure-responsive element and said intake manifold, said valve means being connected to said opening so as to be responsive to the position of said throttle valve relative thereto.

7. Fuel shut-oif apparatus for use with an internal combustion engine having carburetor means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: an opening formed in said carburetor means, said opening being substantially covered by said throttle valve when the latter is in a closed position and uncovered by said throttle valve when the latter is in an open position; a shut-off member for controlling the flow of fluid through said idlingfuel passage, said member including a metering pin aseaisa l3 movable within said idling fuel passage between an open and a closed position, apressur'e-responsive element securedto said pin for actuatirg Same and resilient means 'of said wall in communication with said opening.

8. Fuel shut-off apparatus for use 'with an internal combustion engine having carburetor means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor-means and a throttle valve in said carburetor means, comprising: a pressure-re, sponsive shut-off member for controlling the flowof fluid through said idling fuel passage; conduit means for connecting said shut-off member to said intake vmanifold; a regulator valve having, a passage formingv a portion of said conduit means and-a blocking element movable relative to said passage for controlling flow therethrough,

and a pressure-responsive Wall operativelyconnected to said blocking means and having one of its sides exposed to a substantially constant fluid pressure; and means for placing the opposite side of said wall' in communication with said intake manifold.

' 9. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means, an intake manifold connected with said carburetor menas, an idling: fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a pressure-responsive shut-oifmember. for controlling the flow of fluid through said idling fuel passage; conduitrneans for connecting said shut'off member to said intake manifold; a regulator valve formed with a passage that defines a portion of said conduit means and with acavity intersecting said passage, said regulator valve having a'blocking element slidably disposed in said cavity for controlling flow through said passage, said regulator valve als-o having sensing means responsive to the. differential between atmospheric pressure and intake maifold pressure for effecting movement of said blocking element; and means for placing said sensing means in communication with said intake manifold. v

10. Fuel shut-off apparatus as set forth in claim 9 where said sensing means includes a flexible diaphragm connected to said blocking element and exposed on one side to atmospheric pressure, and spring means constantly opposing the force exterted by atmospheric pressure against said diaphragm.

11. Fuel shut-off apparatus for use with an internal combustion engine having carburetor'means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a shut-off member for controlling the flow of fluid through said idling fuel passage, said member including a metering pin movable .within said idling fuel passage between anopen and a closed position, a pressure-responsive element secured to said pin for actuating same and resilient means constantly biasing said pin toward one of said positions; conduit means for connecting said pressure-responsive element to said intake manifold; a regulator valve having a passage forming a portion of said conduit and a blocking element movable relative to said passage for controlling flow therethrough, and a pressure-responsive wall operatively connected to said blocking means and having one of its sides exposed to a substantially constant fluid pressure; and means for placing the opposite side of said Wall in communication with said intake manifold.

12. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means, an intake manifold connectcdwith said carburetor means ,-an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a'shut-oif member for controlling the flow of fluid through said idling fuel passage, said member including a metering pin movable within said idling fuel passage between an open and "a closedposition, a pressure-responsive element secured to said pin for actuating same and resilient meansconstantly biasing said pin toward one of said positions; conduit means for connecting said pressure-responsive element to said intake manifold; a regulator valve formed with a passage that defines a portion of said conduit means and witha cavity intersecting said passage, said regulator valve having a blocking element slidably disposed in said cavity for controlling flow through said passage, said regulator valve also having sensing means responsive to the differential between atmospheric pressure and intake manifold pressure for effecting movement of said blocking element; and means for placing said sensing means in communication with said intake manifold.

l3. Fuel shut-off apparatus for use With an internal combustionengine having. carburetor means including a float chamber, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a shut-off member for controlling the flow of fluid'through said idling fuel passage; a second shut-01f member for controlling the flow of fuel into said float chamber; and means for moving said shut-off members into a closed position during deceleration of said engine.

14. Fuel shut-off a paratus for use with an internal combustion engine having carburetor means including a float chamber, an intake manifold connected with said carburetor means, an idling fuel passage insaid carburetor means and a throttle valve in said carburetor means, comprising: a shut-off member for controlling the flow of fluid through said idling fuel passage; a second shut-ofl member for controlling the flow of fuel into said float chamber; an opening formed in said carburetor means, said opening being substantially covered by said throttle valve when the latter is in a closed position and uncovered by said throttle valve when the latter is in an open position; and valve means operatively interposed between said opening and said shut-off members for effecting concurrent operation thereof responsive to the position of said throttle valve.

15. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means including a float chamber, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a pressure-responsive shut-off member for controlling the flow of fluid through said idling fuel passage; a second pressure-responsive shut-off member for controlling the flow of fuel into said float chamber; an

opening formed in said carburetor means, said opening being substantially covered by said throttle valve when the latter is in a closed position and uncovered by said throttle valve when the latter is in an open position; conduit means for connecting said shut-off members to said intake manifold; and valve means connected with said opening and interposed in said conduit means for controlling communication between both of said shutoff members and said intake manifold, said valve means being responsive to the position of said throttle valve relative to said opening.

16. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means including a float chamber, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a shut-off member for controlling the flow of fluid through said idling fuel'passage, said member including a metering pin movable Within said idling fuel passage between an open and a closed position, a presbers with the pressure of said intake manifold; and valve means connected with said opening interposed in said conduit means for controlling the flow of fluid therethrough responsive to the position of said throttle valve relative to said opening.

17. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means including a float chamber, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a pressure-responsive shut-off member for controlling the flow of fluid through said idling fuel passage; a second pressure-responsive shut-off member for controlling the flow of fuel into said float chamber; conduit means for concurrently connecting said shut-off members to said intake manifold; a regulator valve having a passage forming a portion of said conduit means and a blocking element that is movable relative to said passage for controlling flow therethrough, and a pressure-responsive wall operatively connected to said blocking means and having one of its sides exposed .to a substantially constant fluid pressure; and means for placing the opposite side of said wall in communication With said intake manifold.

. 18. Fuel shut-off apparatus for use with an internal combustion engine having carburetor means including a float chamber, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a pressure-responsive shut-elf member for controlling the flow of fluid through said idling fuel passage; a second pressure-responsive shut-ofi member for controlling the flow of fuel into said float chamber; conduit means for connecting said shut-off members to said intake manifold; a regulator valve formed with a passage that defines a portion of said conduit means and with a cavity intersecting said passage, said regulator valve having a blocking element slidably disposed insaid cavity for controlling flow through said passage, said regulator valve also having sensing means responsive to the differential between atmospheric pressure and pressure within said intake manifold for effecting movement of said blocking element; and means for placing said sensing means in communication with said intake manifold.

19. Fuel shut-off apparatus for use with the internal combustion engine of a Wheeled vehicle, said engine having carburetor means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprising: a pressure-actuated shut-oft member for controlling theflow of fluid' through said idling fuel passage; means connectingsaid shut-01f member withflsaid intake manifold Cwhereby said shut-off member will be normally urged into aclosed position when the intake manifold vacuum exceeds a predetermined value; and limit valve means: for moving said shut-0d member to an open position regardless of the value of saidintake manifold vacuum when said throttle valve is opened beyond its idling position.

20. Fuel shut-off apparatus for use with the internal combustion engine of a wheeled vehicle, said engine having carburetor means, an intake manifold connected with said carburetor means, an idling fuel passage in said carburetor means and a throttle valve in said carburetor means, comprisingz a pressure-responsive shut-off member for controlling the flow of fluid through said idling fuel passage; conduit means for connecting a chamber in said shut-off member to said intake manifold whereby said shut-01f member Will'normally be urged into a closed.

position when the intake manifold vacuum exceeds a predetermined value; and limit valve meansfor connecting said conduit means to atmosphere and thereby venting said chamber whereby said shut-off member will be moved to an open position regardless of the value of said intake manifold vacuum when said throttle valve is opened beyond its idling position.

21. Fuel shut-off apparatus as set forth in claim 20 where said limit valve means includes a body formed withja chamber defining a portion of said conduit means, said chamber being vented to the atmosphere, a valve element movable within said cavity between an open position wherein said cavity is connected with said intake manifold and a closed position wherein said cavity is connectedto atmosphere,.resilient means constantly biasing said valve element towards said closed position, and motion transmitting means secured to said valve element for urging it out of said closed position to said open position when said throttle valve is moved towards its idling position, said motion transmitting means being engageable by the actuating linkage of said throttle valve.

References Cited in the file of this patent UNITED STATES PATENTS 

